Brown belt...yep. Same thing in karate. Know just enough skill to have some effect but not fully controlled, and are usually young and enthusiastic enough to apply that as vigorously as possible. I hate sparring brown belts, lol.
In my old dojo, that happened at the green belt level (which was the third belt). Some of our brown belts did get big ego's when it came to teaching, but it was more of a power trip then them thinking their technique was all the sudden super duper.